package com.yupi.springbootinit.utils;

import cn.hutool.core.collection.CollUtil;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.ResourceUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * excel转csv
 */
@Slf4j
public class ExcelUtils {
    public static String excelToCsv(MultipartFile multipartFile) {
//        File file=null;
//        try{
//            file= ResourceUtils.getFile("");
//        } catch (FileNotFoundException e){
//            e.printStackTrace();
//        }
        //读取数据
        List<Map<Integer,String>> list= null;
        try {
            list = EasyExcel.read(multipartFile.getInputStream())
                    .excelType(ExcelTypeEnum.XLSX)
                    .sheet()
                    .headRowNumber(0)
                    .doReadSync();
        } catch (IOException e) {
            log.error("表格处理错误",e);
        }
        if(CollUtil.isEmpty(list)){
            return "";
        }
        //转换为csv
        StringBuilder stringBuilder=new StringBuilder();
        //读取表头
        LinkedHashMap<Integer,String> headerMap=(LinkedHashMap) list.get(0);
        List<String> headerList=headerMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
        stringBuilder.append(StringUtils.join(headerList,",")).append("\n");
        //读取数据
        for(int i=1; i< list.size();i++){
            LinkedHashMap<Integer,String> dataMap=(LinkedHashMap) list.get(i);
            List<String> dataList=dataMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
            stringBuilder.append(StringUtils.join(dataList,",")).append("\n");
        }
        return stringBuilder.toString();
    }
}
